1. Field of the Invention
The present invention relates to an original image reading device, and an image information processing apparatus mounting the device and, more particularly, to an original image reading device, applied to an image information processing apparatus such as a facsimile apparatus, an image scanner, or the like, for optically reading image information of an original, and an image information processing apparatus mounting the device.
2. Related Background Art
In recent years, requirements have arisen for compact, lightweight, and inexpensive image information processing apparatuses such as facsimile apparatuses, image scanners, and the like. Especially, in facsimile apparatuses, along with expansion of the market of home facsimile apparatuses for, e.g., a personal use, diversified requirements for designs and functions have arisen in addition to the requirements for compact, lightweight, and inexpensive apparatuses.
As an original image reading device, arranged in such an image information processing apparatus, for optically reading image information of an original, an original reading device employing a reduction reading system as a combination of a line sensor such as a CCD and a reduction optical system, as described in U.S. Pat. No. 4,768,100, a device employing a contact reading system, in which a line sensor having the same length as an original width, an equal-magnification optical system such as a convergent fiber lens array, and a light source such as an LED array are integrally assembled in a frame, as described in U.S. Pat. No. 4,920,431, a device employing a perfect contact reading system, in which a line sensor and a light source are integrally assembled in a frame without using a lens array, and an original image is read while the original is set adjacent on the line sensor, as described in U.S. Pat. No. 4,959,536, and the like are adopted.
FIG. 1 is a sectional view showing a facsimile apparatus as an example of an image information processing apparatus mounting a conventional original image reading device.
The facsimile apparatus includes an original image reading device 1. An original P is separated and fed one by one toward the original image reading device 1 by a separation segment 104 and a feed roller 102. A convey roller 2 presses the fed original P at the reading position of the original image reading device 1, so that the original P is in tight contact with the reading position. The convey roller 2 also conveys the original P. A recording head 110 records image information read by the original image reading device 1 or image information transmitted from an external device on a recording medium W. A platen roller 112 presses the recording medium W at the recording position of the recording head 110, so that the recording medium W is in tight contact with the recording position. In addition, the platen roller 112 conveys the recording medium W. An operation panel 120 is provided with switches for accepting operation inputs, and a display unit for displaying messages and states of the apparatus. The facsimile apparatus also includes a system control board 130, and a power supply 140. Note that the feed roller 102, the convey roller 2, and the platen roller 112 are coupled to drive force transmission members such as motors, gears, and the like (not shown) arranged on one or both sides in a direction perpendicular to the drawing surface, and are rotated by these members.
The above-mentioned components are integrally locked on a main body frame 106.
However, in order to meet requirements for a compact, lightweight, and inexpensive structure, and diversified designs and functions of the image information processing apparatus, the following technical subjects remain unsolved in the conventional image reading device and the image information processing apparatus.
(1) As the apparatus is rendered compact and light weight, it is difficult to assure assembling position precision. As a result, parts precision must be further improved, thus preventing the manufacture of an inexpensive apparatus.
(1-1) In the conventional image information processing apparatus, since various components are integrally locked on the main body frame, the main body frame assures rigidity of the image information processing apparatus. Therefore, as the apparatus is rendered compact and lightweight, the rigidity of the main body frame is decreased, thus impairing assembling position precision of the respective components. In particular, a decrease in rigidity of the main body frame impairs positional precision between the original image reading device and the convey roller, thus degrading image reading performance, and original convey performance. PA1 (1-2) In order to realize a compact, lightweight apparatus, for example, the dimensions of a gear module are decreased to decrease the gear diameter. In this case, precision of the distance between the centers of gears must be further improved. As a result, it is difficult to reduce parts cost. PA1 (2-1) In the conventional image information processing apparatus, since various components are integrally locked on the main body frame, the shape of the main body frame determines the design of the product. Therefore, when the design is changed, the shape of the main body frame must be changed first, and the design load, cost of, e.g., molds, and cost upon a change in production equipment prevent the manufacture of an inexpensive image information processing apparatus. PA1 (2-2) When the functions of the image information processing apparatus are changed, various loads prevent the manufacture of an inexpensive image information processing apparatus like in the change in design. PA1 (3-1) In consideration of the production process of the image information processing apparatus, after components mounting the original image reading device are assembled on the main body frame of the image information processing apparatus, the function check test of the image information apparatus is conducted. As a result of the test, for example, when a defect is found in the original image reading device, other assembled components must be disassembled from the main body frame, and the original image reading device must be replaced or repaired. Furthermore, the original image reading device must be assembled on the main body frame again, and then, adjustment must be performed. PA1 (3-2) For example, when the original image reading device malfunctions during use of the image information processing apparatus, the original image reading device must be disassembled from the main body frame of the image information processing apparatus together with other components, and must be replaced or repaired. Furthermore, the original image reading device must be assembled on the main body frame again, and then, adjustment must be performed.
(2) Loads upon changes in design and function are considerable, and prevent the manufacture of an inexpensive apparatus.
(3) Replacement and repair are not easy when a defect or malfunction is found.
In particular, in the contact reading system, since the focal depth is relatively shallow, an original and the reading surface must be precisely aligned. In this case, when the convey roller 2 and the reading device 1 are independently locked on the main body frame 106 of the apparatus like in the conventional apparatus, it is difficult to align the roller 2 with the reading surface of the reading device 1, thus undesirably prolonging an assembling time of the overall apparatus.